Fuel intake device for fuel systems

Abstract

A fuel intake device (20) for a fuel system (10) having a fuel tank (14) for containing a supply of fuel (16) and an internal fuel feed line (18) which is disposed internally of the fuel tank (14). The fuel intake device (20) is operative to provide uninterrupted fuel flow in icing conditions and is characterized by a flexible fuel filter (40) having a plurality of primary flow apertures (42) apertures therein for facilitating a primary flow P F of fuel therethrough, a bypass means (50) for providing a secondary flow S F of fuel to the internal fuel feed line (18) when an accumulation of ice (80) restricts the primary flow P F of fuel through the primary flow apertures (42), and force bias means (60) for rapidly reconfiguring the flexible fuel filter (40) for forcibly shedding the accumulation of ice (80), thereby restoring the primary flow P F of fuel. The flexible fuel filter (40) is reconfigurable from an extended position to a collapsed position in response to a threshold pressure differential across the flexible fuel filter (40). Upon sensing the threshold pressure differential, the bypass means (50) provides a secondary fuel flow S F which effects a nominal pressure differential across the flexible fuel filter (40). In response to the nominal pressure differential, the force bias means (60) is actuated or released so as to rapidly expand the flexible fuel filter (40).

What is claimed is: 
     
       1. A fuel intake device (20) for a fuel system (10), the fuel system (20) having a fuel tank (14) for containing a supply of fuel (16) and an internal fuel feed line (18), the fuel intake device (20) being characterized by: a flexible fuel filter (40) enveloping an end portion (18 E ) of the internal fuel feed line (18) and having a plurality of primary flow apertures (42) apertures therein for facilitating a primary flow P F  of fuel (16) therethrough, said flexible fuel filter (40) being reconfigurable from an extended position to a collapsed position in response to a threshold pressure differential across said flexible fuel filter (40);   bypass means (50), responsive to said threshold pressure differential, for providing a secondary flow S F  of fuel (16) to said internal fuel feed line (18) when an accumulation of ice (80) restricts said primary flow P F  of fuel through said primary flow apertures (42), said secondary flow S F  of fuel (16), furthermore, effecting a nominal pressure differential across said flexible fuel filter (40);   force bias means (60), responsive to said nominal pressure differential, for rapidly reconfiguring said flexible fuel filter (40) from said collapsed position to said extended position for forcibly shedding said accumulation of ice (80), thereby restoring said primary flow P F  through said primary flow apertures (42).   
     
     
       2. The fuel intake device (20) according to claim 1 wherein said bypass means (50) includes a pressure-actuated bypass valve (52) disposed in combination with said flexible fuel filter (40), said pressure-actuated valve (52) providing said secondary fuel flow S F  to said internal fuel feed line (18) through said flexible fuel filter (40). 
     
     
       3. The fuel intake device according to claim 1 wherein said bypass means (50) includes a secondary flow tube (106) disposed in fluid communication with the fuel feed line (18), a mechanically-actuated bypass valve (110) for providing the secondary fuel flow S F  through the tube (106), and a mechanical linkage arrangement (114) for alternately opening and closing the bypass valve (110) in response to displacement of the flexible fuel filter (40). 
     
     
       4. The fuel intake device (20) according to claim 1 wherein said flexible fuel filter (40) is a flexible metallic bellows (42). 
     
     
       5. The fuel intake device (20) according to claim 1 wherein said force bias means (60) includes a coil spring (62) disposed between an upper and lower portion (44 U , 44 L ) of said flexible fuel filter (40). 
     
     
       6. The fuel intake device (20) according to claim 1 wherein said force bias means (60) is defined by a characteristic spring rate of said flexible fuel filter (40). 
     
     
       7. The fuel intake device (20) according to claim 1 further characterized by a shroud member (90) disposed about the flexible fuel filter (40), said shroud member (90) including a lower end portion (92) extending into a sump region (26) of the fuel tank (14) and an upper end portion (94) disposed in sealed combination with the internal fuel feed line (18), said lower end portion (92) defining an opening for facilitating fuel flow to the flexible fuel filter (40). 
     
     
       8. The fuel intake device (20) according to claim 1 wherein the threshold pressure differential is between about 1.5 lbs/in 2  to about 2.5 lbs/in 2 , wherein said nominal pressure differential is at least 1.0 lbs/in 2  less than said threshold pressure differential. 
     
     
       9. The fuel intake device (20) according to claim 2 wherein said flexible fuel filter (40) is a flexible metallic bellows (42). 
     
     
       10. The fuel intake device (20) according to claim 2 wherein said force bias means (60) includes a coil spring (62) disposed between an upper and lower portion (44 U , 44 L ) of said flexible fuel filter (40). 
     
     
       11. The fuel intake device (20) according to claim 2 wherein said force bias means (60) is defined by a characteristic spring rate of said flexible fuel filter (40). 
     
     
       12. The fuel intake device (20) according to claim 2 further characterized by a shroud member (90) disposed about the flexible fuel filter (40), said shroud member (90) including a lower end portion (92) extending into a sump region (26) of the fuel tank (14) and an upper end portion (94) disposed in sealed combination with the internal fuel feed line (18), said lower end portion (92) defining an opening for facilitating fuel flow to the flexible fuel filter (40). 
     
     
       13. The fuel intake device (20) according to claim 2 wherein the threshold pressure differential is between about 1.5 lbs/in 2  to about 2.5 lbs/in 2 , wherein said nominal pressure differential is at least 1.0 lbs/in 2  less than said threshold pressure differential. 
     
     
       14. The fuel intake device (20) according to claim 3 wherein said flexible fuel filter (40) is a flexible metallic bellows (42). 
     
     
       15. The fuel intake device (20) according to claim 3 wherein said force bias means (60) includes a coil spring (62) disposed between an upper and lower portion (44 U , 44 L ) of said flexible fuel filter (40). 
     
     
       16. The fuel intake device (20) according to claim 3 wherein said force bias means (60) is defined by a characteristic spring rate of said flexible fuel filter (40). 
     
     
       17. The fuel intake device (20) according to claim 3 further characterized by a shroud member (90) disposed about the flexible fuel filter (40), said shroud member (90) including a lower end portion (92) extending into a sump region (26) of the fuel tank (14) and an upper end portion (94) disposed in sealed combination with the internal fuel feed line (18), said lower end portion (92) defining an opening for facilitating fuel flow to the flexible fuel filter (40). 
     
     
       18. The fuel intake device (20) according to claim 3 wherein the threshold pressure differential is between about 1.5 lbs/in 2  to about 2.5 lbs/in 2 , wherein said nominal pressure differential is at least 1.0 lbs/in 2  less than said threshold pressure differential.